<?php
/**
 * This file houses the XmlOutputProtocol class.
 *
 * Copyright (c) 2010, Kalkomey Enterprises, Inc.
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 * 
 * - Redistributions of source code must retain the above copyright notice, this list
 *   of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright notice, this 
 *   list of conditions and the following disclaimer in the documentation and/or other
 *   materials provided with the distribution.
 * - Neither the name of the Kalkomey Enterprises, Inc. nor the names of its 
 *   contributors may be used to endorse or promote products derived from this 
 *   software without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
 * SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
 * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 * 
 * @license http://www.opensource.org/licenses/bsd-license.php New BSD License
 * @copyright Copyright (c) 2010, Kalkomey Enterprises, Inc.
 * @link http://code.google.com/p/swerv
 * @package Shared
 * @subpackage Protocols
 */

/**
 * The XmlOutputProtocol class converts a response object into XML.
 *
 * @package Shared
 * @subpackage Protocols
 */
class XmlOutputProtocol extends OutputProtocol {

	/**
	 * Converts a response object into XML.
	 *
	 * @uses XmlOutputProtocol::getObjectAsXml()
	 * @uses StringUtility::toLowerCase()
	 * @uses StringUtility::formatXmlString()
	 * @uses SiteContext::$controller
	 * @uses SiteContext::$action
	 *
	 * @return string
	 */
	public function getOutput(&$responseObj) {
		$urlController = str_replace('_controller', '', StringUtility::toLowerCase(SiteContext::$controller));
		$urlMethod = StringUtility::toLowerCase(SiteContext::$action);
		$controller = SiteContext::$controller;
		$action = SiteContext::$action;
		$className = get_class($responseObj);
		$xmlWriter = new XMLWriter();
		$xmlWriter->openMemory();
		$xmlWriter->startElement($className);
		$xmlWriter->writeAttribute('xmlns', API_URL . "/xml/{$urlController}/{$urlMethod}");
		$xmlWriter->writeAttribute('xmlns:xsi', 'http://www.w3.org/2001/XMLSchema-instance');
		$xmlWriter->writeAttribute('xsi:schemaLocation', API_URL . "/xml/{$urlController}/{$urlMethod} " . API_URL . "/doc/main/schema/xsd/{$controller}/{$action}");
		$this->getObjectAsXml($responseObj, $xmlWriter);
		$xmlWriter->endElement();
		$xml = $xmlWriter->flush();
		$xml = StringUtility::formatXmlString($xml);
		return $xml;
	}

	/**
	 * Converts an object into XML.
	 * Note: this is a recursive method
	 *
	 * @param object &$responseObj the response object being converted to XML
	 * @param object &$xmlWriter an XMLWriter instance used to build the XML
	 *
	 * @return void
	 */
	private function getObjectAsXml(&$responseObj, &$xmlWriter) {
		foreach ($responseObj as $paramName => $value) {
			$xmlWriter->startElement($paramName);
			if (is_object($value)) {
				$this->getObjectAsXml($value, $xmlWriter);
			} elseif (!is_array($value)) {
				$xmlWriter->text($value);
			}
			$xmlWriter->endElement();
		}
	}

}
